Tool for making up a bell and spigot pipe joint

Abstract

A unitary tool assembly is disclosed for making up bell and spigot joints to couple adjacent pipe sections. The tool includes forward and rearward pipe engaging subassemblies and an intermediate linkage mechanism. The forward subassembly, which straddles a pipe section having a bell end, includes a reciprocative actuator which, through the linkage mechanism, selectively causes toothed cams carried by the rearward subassembly to engage and disengage a pipe section having a spigot end and straddled by the rearward subassembly. When the actuator delivers a power stroke, the toothed cams securely engage the pipe section with the spigot end, and the rearward subassembly is simultaneously pulled toward the forward subassembly such that successive strokes of the actuator effect a ratcheting action in which the bell and spigot joint is made up through a series of stepwise movements of the pipe sections together. Each of the pipe engaging subassemblies includes a partial collar adapted to loosely fit over the pipe section it straddles to thereby provide support for the tool as it is used.

I claim: 
     
       1. A unitary tool assembly for coupling a pair of adjacent pipe sections of the type having respective bell and spigot joint elements by pulling the bell and spigot together into frictional engagement, said tool assembly comprising: (A) a forward pipe engaging sub-assembly, said forward subassembly including: 1. a first partial collar, said first partial collar having: a. a semi-circular section having first and second ends;   b. a first tangential extension joining said first semi-circular section end of said first partial collar; and   c. a second tangential extension joining said second semi-circular section end of said first partial collar;     2. a first pair of parallel, vertically spaced, upper and lower pivot journals fixed to and directed outboard from said first tangential extension of said first partial collar;   3. a second pair of parallel, vertically spaced, upper and lower pivot journals fixed to and directed outboard from said second tangential extension of said first partial collar;     
     
     
       4. reciprocative actuator means, said actuator means first and second slots for respectively pivotally receiving said first and second of pivot journals; (B) a rearward pipe engaging sub-assembly, said rearward subassembly including: 1. a second partial collar, said second partial collar having: a. a semi-circular section having first and second ends.   b. a first tangential extension joining said first semi-circular section end of said second partial collar;   c. a second tangential extension joining said second semi-circular section end of said second partial collar;   d. a first aperture disposed proximate the junction of said semi-circular section and said first tangential extnsion; and   e. a second aperture disposed proximate the junction of said semi-circular section and said second tangential extension;     2. a first toothed cam pivotally affixed to said second partial collar adjacent said first aperture and adapted to pivot between a first position in which said first cam is withdrawn outside the space within said second partial collar and a second position in which said first cam extends through said first aperture into the space within said second partial collar with the teeth of said first cam facing inwardly; and   3. a second toothed cam pivotally affixed to said second partial collar adjacent said second aperture and adapted to pivot between a first position in which said second cam is withdrawn outside the space within said second partial collar and a second position in which said second cam extends through said second aperture into the space within said second partial collar with the teeth of said second cam facing inwardly;     (C) a linkage mechanism coupling said forward sub-assembly and said rearward sub-assembly, said linkage mechanism including: 1. a first link member extending from said actuator means to said first cam;   2. A second link member extending from said actuator means to said second cam;   3. said first and second link members being respectively pivotally affixed to said actuator means at positions offset from said pivot journals such that reciprocating motion of said actuator means about said pivot journals alternatively pulls said forward and rearward sub-assemblies toward one another and permits them to spread apart and, during the actuation motion pulls said forward and rearward sub-assemblies toward one another, also pulls said first and second cams toward their respective second positions; whereby the spigot may be inserted into the bell and said tool subsequently emplaced over the bell with said forward pipe engaging sub-assembly straddling the pipe carrying the bell and said rearward pipe engaging sub-assembly straddling the pipe carrying the spigot such that said actuator means may be operated reciprocally to cause said teeth to alternately engage and disengage the pipe carrying the spigot to thereby ratchet said tool into a position at which said first partial collar bears against the bell whereupon further reciprocating operation of said actuator pulls the pipe pair together until the spigot is firmly frictionally seated within the bell.       
     
     
       2. The unitary tool assembly of claim 1 in which said reciprocative actuator means further comprises: (A) a generally horseshoe shaped yoke having: 1. a semi-circular central portion;   2. first and second tangentially extending vertical legs joining first and second ends of said semi-circular portion; and   3. an outwardly extending handle fixed to said semi-circular portion; and in which:       (B) said first and second slots are respectively situated proximate the lower terminations of said first and second legs.   
     
     
       3. The unitary tool assembly of claim 2 in which each case of said slots is V-shaped, the legs of the V being configured convex outwardly with the length of each leg of the V and the distance between the unjoined ends of the V being the same and corresponding to the distance between said pivot journals of each pivot journal pair, whereby said yoke pivots about said upper pivot journal of each pivot journal pair during a stroke of said yoke toward said rearward pipe engaging sub-assembly, and said yoke pivots about said lower pivot journal of each pivot journal pair during a stroke of said yoke away from said rearward pipe engaging sub-assembly. 
     
     
       4. The unitary tool assembly of claim 3 in which said linkage mechanism further includes: (A) at least two elongated guides extending between said forward sub-assembly and said rearward sub-assembly, each elongated guide being fixed to said forward sub-assembly and slideably engaging said rearward subassembly; and   (B) a compression spring encompassing each said elongated guide and adapted to bias said forward sub-assembly and said rearward sub-assembly apart.   
     
     
       5. The unitary tool assembly of claim 4 which further includes first and second integral, outwardly directed stiffening flanges disposed, respectively, on the outer peripheries of said first and second partial collars. 
     
     
       6. The unitary tool assembly of claim 1 in which each of said first and second link members comprises a hydraulic ram. 
     
     
       7. The unitary tool assembly of claim 6 in which each of said slots is V-shaped, the legs of the V being configured convex outwardly with the length of each leg of the V and the distance between the unjoined ends of the V being the same and corresponding to the distance between said pivot journals of each pivot journal pair, whereby said reciprocative actuator pivots about said upper pivot journal of each pivot journal pair during a stroke of said reciprocative actuator toward said forward pipe engaging sub-assembly, and said reciprocative actuator pivots about said lower pivot journal of each pivot journal pair during a stroke of said reciprocative actuator away from said forward pipe engaging sub-assembly. 
     
     
       8. The unitary tool assembly of claim 7 in which said linkage mechanism further includes: (A) at least two elongated guides extending between said forward sub-assembly and said rearward sub-assembly, each said elongated guide being fixed to said forward sub-assembly and slideably engaging said rearward subassembly; and   (B) a compression spring encompassing each said elongated guide and adapted to bias said forward sub-assembly and said rearward sub-assembly apart.   
     
     
       9. The unitary tool assembly of claim 8 which further includes first and second integral, outwardly directed stiffening flanges disposed, respectively, on the outer peripheries of said first and second partial collars.